VIA is planning to swap its free “E route” trollies for quieter, sleeker buses when it expands the service next summer.

VIA’s board of trustees voted Tuesday to spend $7.3 million on 15 New Flyer buses that run on compressed natural gas.

“The trollies are nearing the end of their operational life,” said Gary Glasscock, VIA’s vice president of fleet and facilities.

The agency plans to buy the buses from Dallas Area Rapid Transit, which has a surplus of them, Glasscock said. VIA must get approval from the Federal Transit Administration before making a purchase through the other agency’s contract with New Flyer.

If the FTA approves the deal, the buses likely will be delivered in May, Glasscock said. At that point, VIA plans to make the E route service permanent and expand it to serve more locations such as the Pearl, Southtown and the Blue Star Arts Complex.

The 40-foot buses VIA plans to purchase look similar to its existing fleet of buses that run on compressed natural gas, which burns cleaner than traditional fuel.

“We’re trying to make a statement with the buses we’ll be placing on the E route,” Glasscock said.

They might also be more comfortable.

“Based on the Dallas contract, I think they have a little more padding than what we’re used to here,” Glasscock said.

Marc Harrison, secretary of VIA’s board, said he supported replacing the trollies with the new vehicles because emissions and noise concerns are greater in the downtown area where the E route runs.

“If the CNG buses are E route only, they’ll be in a confined area downtown, and CNG runs at a quieter decibel level,” he said. “I think downtown is the best place for them right now.”

VIA launched the E route in late March to run between downtown entertainment and tourist venues including the Majestic Theater and the Tobin Center. The $100,000 pilot program was scheduled to expire last month, but the agency’s board voted to extend it until the planned expansion takes effect.

The service made 7,800 one-way passenger trips as of the end of August, according to VIA. Ridership peaked in July, when it made 2,000 trips.

The current E route trollies operate Tuesday through Saturday from 6 p.m. until about midnight. They come every 10 minutes and serve parts of East Commerce, Navarro, North St. Mary’s and West Market streets.